The present invention relates to a new and improved solenoid operated exhaust air damper for use in exhaust air systems which utilize exhaust air fans. Such exhaust air systems are commonplace and can be found in virtually every household bathroom and kitchen. They are found in houses, apartments, hotels, office buildings, industrial complexes and factories and so forth.
There are many varieties and designs of exhaust air fans which are in common use today.
The typical installation of a household exhaust air system utilizes an exhaust air fan mounted in the ceiling, drawing its suction directly from the room. Typically, the exhaust air fan has a decorative louver covering the suction. The fan exhausts the air into a duct, normally made of sheet metal, up through the ceiling and roof of the building. Normally there is some sort of a raincap atop the exhaust duct to keep rain, snow and the elements out of the exhaust duct system.
Typical exhaust air fans are designed to run on household current, and are wired to an on/off switch or timer normally located in the vicinity of the light switch to the room.
With the normal installation, there is no damper or other means of closing the exhaust duct when the fan is not in use. Thus, there is an open passageway for air to either enter or leave the house. In the winter the heated inside air can flow, by convection, or by venturi suction, directly to the outside. If, for example, the exhaust duct is circular with a four inch diameter, the result is that the exhaust air system represents a four inch hole in the roof of the building.